1. Technical Field of the Invention
The present invention relates to a display device for a projector, and more particularly to a technique which is effectively applicable to image processing of inputted image data in a liquid crystal display device in which amplified analogue video signals are inputted after being subjected to the phase development.
2. Description of the Related Art
Recently, a liquid crystal display device has been popularly used as a display terminal of any equipment ranging from a miniaturized display device to a so-called OA equipment. The liquid crystal display device is basically constituted of a so-called liquid crystal panel (a liquid crystal display element or a liquid crystal cell) which inserts a layer (a liquid crystal layer) formed of liquid crystal composition between a pair of insulation substrates at least one of which is made of a transparent glass plate, a plastic substrate or the like.
The liquid crystal panel is roughly classified into a liquid crystal panel adopting a method (a simple matrix method) in which the pixel formation is performed by changing the orientation direction of liquid crystal molecules constituting the liquid crystal composition of desired pixel portions by selectively applying voltages to various types of electrodes for forming pixels formed on the insulation substrate, and a liquid crystal panel adopting a method (an active matrix method) which performs the pixel formation by changing the orientation direction of liquid crystal molecules of pixels which are arranged between pixel electrodes connected to active elements and reference electrodes which face the pixel electrodes in an opposed manner by forming the above-mentioned various types of electrodes and active elements for selecting pixels and selecting the active elements.
An active-matrix type liquid crystal display device which includes active elements (thin film transistors, for example) provided to respective pixels and performs the switching driving of these active elements has been popularly used as a display device of a notebook type personal computer or the like. In general, the active matrix type liquid crystal display device has been adopting a so-called vertical electric field method in which an electric field for changing the orientation direction of a liquid crystal layer is applied between electrodes formed on one substrate and electrodes formed on another substrate. Further, a liquid crystal display device which adopting a so-called lateral electric field IPS (In-Plane-Switching) method which sets the direction of an electric field applied to a liquid crystal layer to a direction substantially parallel to surfaces of substrates has been commercialized.
On the other hand, as a display device which uses the liquid crystal display device, a liquid crystal projector has been commercialized. In the liquid crystal projector, an illumination light emitted from a light source is emitted to a liquid crystal panel and an image on the liquid crystal panel is projected onto a screen. The liquid crystal panel used in the liquid crystal projector is classified into a reflection type projector and a transmission type projector. With respect to the reflection type projector, the approximately whole area of the pixels can be used as an effective reflection surface and hence, the reflection type projector is advantageous compared with a transmission type projector in view of the miniaturization, the acquisition of high definition and high brightness of the liquid crystal panel. Further, among the active matrix type liquid crystal display devices, there has been known a so-called liquid crystal display device incorporating driving circuits which also forms driving circuits for driving pixel electrodes on a substrate on which pixel electrodes are formed.
Further, with respect to the liquid crystal display device incorporating driving circuits, there has been known a reflection type liquid crystal display device (Liquid Crystal on Silicon, hereinafter also referred to as LCOS) which does not mount pixel electrodes and driving circuits on an insulation substrate but mounts them on a semiconductor substrate.
Further, as a driving method of the liquid crystal display device incorporating driving circuits, there has been known a driving method which inputs video signals to a liquid crystal display device from the outside in a form of analogue signals and outputs the video signals to a liquid crystal panel by sampling the video signals using driving circuits.